Steam engine



Sept. 27, 1927. 1,643,671 N. M. LOWER STEAM ENGINE Filed July 14. 1922 4 SheetsSheet 1 M61200: Amrwy ZZZ .1, W

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STEAM ENGINE Filed July 14. 1922 4 Sheets-Sheet 4 I y a 44 fig 2 [)2 van 602 5 %QZ76ZVZ%ZOZUY Patnted Sept. 27, 1927.

UNITED STATES PATENT OFFICE.

NATHAN M. LOWER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR LOCOMOTIVE STOKER COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIA.

Application filed July 14,

The invention relates to that type of steam engines in which the valve mechanism is actuated or controlled by the piston; and its object is to provide governing means for controlling the action of the engine under varying loads.

An efiicient and desirable form of the invention is hereinafter described, and is illustrated in the accompanying drawings, in

which I Fig. 1 is a longitudinal central section through the engine cylinder and through the valve casing;

Fig. 2 is an end view of the engine with the cover plate of the valve casing removed;

Fig. 3 is a longitudinal sectional view on the line 33 of Fig. 2;

Fig. 4 is a detail of a valve for regulating the governor;

Fig. 5 is a sectional view on the line 55 o -f Fig. 1;

Fig. 6 is a sectional view on the line 6-6 of Fig. 5;

Fig. 7 is a detail plan view of valve mechanism;

Figs. 8 and 9 are detail sections on the lines 88 and 99, respectively, of Fig. 7;

Fig. 10 is a detail section on the line 1Q-10 df Fig. 1: and Fig. 11 is a section on line 11-11 of Fig. 6.

The engine is of the type frequently employed independentlv of a crank shaft, as, for example, where the piston *rod takes the form of a gear rack for turning a gear 35 and in which the valve mechanism is actuated through the medium of a rod engaged by the engine piston.

The cylinder of the engine is represented at 15. its piston at 16, and its piston rod at 17. The valve actuating rod is shown at 18 as being located upon the axis of the cylinder and extending through the piston 16 and into a suitable bore 19 in the piston rod 17. In the present instancethe rod 18 is spiral, in effect threaded to engage a complementary nut 20 carried by the piston 16, the rod 18 being turned in opposite directions during the out and instroke of the iston. The valve and governing mechanism is housed within a casing .21, secured or formed upon the cylinder head 22.-

' The distributing valve is shown at 23, and takes the form of" a pair of rigidly united pistons 24, 25, diifering in'diameter. Steam STEAM ENGINE.

1922. Serial No. 575,062.

is led to the engine through 'a pipe 26, which delivers to the annular chamber 27 inclosed between the pistons 24, 25, within which chamber constant pressure is maintained. Ports 28, 29, controlled by the pistons 24, 25, lead, respectively, to the outer and inner end of the cylinder 15. The main exhaust of the engine is shown at 30.

When either of the ports 28. 29, is cut off from the steam supply, but is uncovered by the corresponding valve piston. it acts as an exhaust and discharges into the chamber of the casing 21. the communication therewith of the port 28 being through the port 31. as shown in Figs. 2 and 3. From this chamber thereleads a main exhaust passage 30 (Fi s. 2. 5. 6 and 11).

As illustrated the distributing valve is shifted to deliver steam to the port 28 by the overbalancing pressure upon the larger piston 24, and is forced in the opposite direction to deliver steam through the port 29 b the action of wedging elements as hereinafter described.

The outer end of the rod 18 proiects into the casing 21 and carries a pinion 32. which me hes with a gear rack 33 upon which is longitudinallv mounted a wedging element 34. A stem 35. proiecting from the smaller end of the wedging element 34, extends looselv through a controlling valve 36. taking the form of a piston having an annular channel 37. This valve is shifted at the end of each stroke of the piston 16 by the engagement with it of a. head 38 on the outer end of the stem and a shoulder 39 at its inner end.

The channel or valve cavity 37 is adapted. when the valve 36 is in one position. to open communication between a steam duct 40. which mav lead directly from the pipe 26. and a duct 41 leading to the outer end of a cylinder chamber 42. within which reciprocates a piston 43. In another position of the valve 36 the duct 41 is brought into communication with an exhaust duct 44, thereby relieving the pressure in the chamber 42 and permitting the piston 43 to make a return stroke under the influence of a spring 45, acting upon a piston 46, carried by the stem 47 of the valve 43, and reciprocating as a pump plunger in a cylinder 48.

The chamber of the cylinder 48 beyond the plunger 46 is in communication with an oil reservoir 49, through a duct 50 as shown in dotted lines in Fig. 3, controlled by a check-valve 51 opening toward the chamber of the cylinder. same end of the cylinder 48 through a pipe 53. which delivers back into the upper end of the oil reservoir, as shown at 54. The flow of oil through the pipe 53 may be regulated by means of a hand-controlled valve 55, thus varying the load on the piston 43.

A second wedge element 56 is in sliding engagement with the wedging face of the.

As the piston 16 reaches the end of its instroke the shoulder 39 engages the valve 36 and shifts it to connect the steam port 40 with the cylinder of the chamber 42. thereby advancing the piston 43 and plunger 46 at a regulated speed, determined by the positioning of the valve 55. At the same time the piston valves 24, 25, will have been shifted by the wedging action of the element 34 to uncover the port 28 to connect it with the exhaust port 31 and to slightly open the port 29 for. the admission of steam. The outstroke of the piston '16 will commence slowly. but the advance of the wedge element 56 will tend to further shift the piston valves 24. 25, in the same direction, the rapidity or extent of this shifting action. however, depending upon the position of the valve 55 40 and the load imposed upon the engine, for as the piston 16 is advanced the wedging element 34 is shifted in the direction in which the element '56 is now traveling, and the two wedging elements being oppositely tapered one tends to counteract the wedging action of the other.

Should the load imposed upon the engine be comparatively light the element 34 will advance more rapidly than the element 56. and steam will be cut off from the engine by the automatic shifting of the distributing valve. Should the-load imposed upon the engine be increased during the outstroke the piston 16 will momentarily hesitate, checking the movement of the wedge element 34. and permitting the element 56-the advance movement of which is constant-to cause a further shifting of the distributing valve to increase the steam supply to the engine.

As the piston 16 approaches the end of its outstroke the head 38 engages the valve 36 and shifts it to open the port 41 to the exhaust port 44, permitting the return of the piston 43, under the action of the spring 45, withdrawing the wedge 56 and allowing the A duct 52 leads from the shifting of the distributing valve, by the action of the overbalancing pressure upon the piston 24, to admit steam to the outer end of the cylinder 15 and exhaust'it from the inner end thereof.

Should the engine become stalled by overloading, a not infrequent incident in such service as the stoking of locomotives, it may become necessary to reverse the movement of the piston 16 during the power stroke. This is accomplished b relieving the pressure upon the face of t e piston 43, permit ting it to return under the influence of the spring 45, and withdrawing the wedging element 56.

As a simple means for effecting this action there is shown a steam or exhaust pipe 60, provided with steam valve 60 and exhaust valve 60". Opening exhaust valve 6O relieves the pressure on piston 43 and allows spring 45 to act, causing the reverse of the movement of piston 16. Should it be desired to reverse the piston 16 during the instroke, steam valve 60 is opened.

The casing of the valve 55 may be located at any convenient position, even at a considerable distance from the engine. For example, in locomotive stoker service this valve may be placed within the locomotive cab, though the stoker engine may be positioned below the cab floor.

A relief port 61 connects the upper end of the cylinder 48 with the oil reservoir 49, to permit the escape of'any oil which may work pastthe piston 46.

While an operative and preferred form of construction is shown. the valve and governing mechanism ma be variously modified without departing rom the scope of the invention. I

I claim as my invention 1. In a reciprocating engine of the type described, the combination with a distributing valve and the piston of the engine, of means including a mechanically operated device for shifting the valve, a fluid motor for actuating such device, a valve controlling such motor and openable by the engine piston at the end of its stroke, and means movable by the engine piston for regulating the action of the valve-opening means.

2. The combination with a fluid actuated engine, of a distributing valve, a. pair of slidably engaged differential wedges for effecting the movement'of the'valve', means for driving one of such wedges at uniform speed, and means for driving the other of such wedges at a speed proportionalwith that of the engine. 1

3. The combination with a fluid actuated engine, of a distributing valve, means including a wedge for shifting the valve, means for advancing such wedge at uniform speed, a Wedge for counteracting the action of the first-namediwedge, and means for advancing the second-named wedge at a speed proportional with that of the en ine piston.

4. The combination with a fluid actuated engine, of a distributing valve, a pair of slidably engaged differential WECi GS for ef footing the movement of the vaIve, means for driving one of such Wedges at uniform speed, means for driving the other of such wedges at a speed proportional with that of the engine, and means for adjusting the speed of the wedge having a uniform speed 5. The combination with a fluid actuated engine, of a distributing valve, means ineluding a wedge for shifting the valve, means for advancing such wedge at uniform speed, a wedge for counteracting the action of the first-namede wedge,v means for advancing the second-named wedge at a speed proportional with that of the engine piston, and means for adjusting the speed of the wedge having a uniform speed.

6. The combination with a fluid "actuated engine, of a distributing valve, a pair ofv slidably engaged differential wedges for effecting the movement of the valve, means for driving oneof such wedges at uniform speed, means for driving the other of such wedges at a speed proportional with that of the engine, and means for reversing the direction of movement of the wedge having uniform speed during its advance stroke.

7. In a steam engine, a cylinder, a piston reciprocating in said cylinder, a distributing valve and means including an elementrotated by the movement of the piston for variably regulating the valve movement.

8. In a steam engine, a cylinder, a piston reciprocating in said cylinder, a distributing valveadapted to be shifted to one extreme position by steam pressure, means associated with said piston for operating said valve in the opposite direction, and means controlled by the speed of the engine for regulating the extent of the movement of said valve by the first-named means.

9. In a steam engine, a cylinder, a. piston reciprocating therein, a spiral rod engaging a complementary opening in the piston and carrying a pinion, a distributing valve having a lateral shoulder on its stem, a' pair of cooperating wedge elements acting on such shoulder, a gear rack on one of such elements, engaging the pinion, a fluid motor for advancing the other wedge element, the valve of such motor being controlled by the gear driven element.

10. In a steam engine, a cylinder, a. piston reciprocating therein, a spiral rod engagin a complementary opening in the piston an carrying a pinion, a3 distributing valve steam actuated in one direction and having a lateral shoulder on its stem, a pair of cooperating Wedge elements acting on such shoulder, a gear rack on one of such elements-engaging the pinion, a fluid motor for advancing the other wedge element, the valve of such motor being controlled by the gear driven element. I

11. In a steam engine, a cylinder, a piston reciprocating therein, a spiral rod engaging a complementary opening in the piston and carrying a pinion. a distributing valve having a lateral shoulder on its stem, a pair of cooperatin wedge elements acting on such shoulder, a gear rack on one of such elements engaging the pinion, a fluid motor for advancing the other wedge element, the valve of such motor being controlled by the gear driven element, a plunger pump actuated by the motor, and means for restricting the discharge passage of the pump.

12. In a steam engine, a cylinder, a piston reciprocating therein, a spiral rod engaging a complementary opening in the piston and carrying a pinion. a distributing valve having a lateral shoulder on, its stem, a pair of cooperating wedge elements acting on such carrying a pinion. a distributing valve having a lateral shoulder on its stem, a pair of cooperating wedge elements acting on such shoulder, a gear rack on one of such elements 1 engaging the pinion, a fluid motor for advancing the other wedge element, the valve of such motor being controlled by the gear driven element. and manually controlled means for admitting driving pressure to the motor.

14. In a steam engine, in combination with the cylinder and a reciprocating piston therein. of a distributing valve under constant steam pressure in one direction, means for moving the valve in the opposite direction, such means comprising a mechanical element. a motor for actuating such element and operative connection between the engine piston and the valve of such motor whereby the motor is controlled by the piston.

15. In a steam engine, in combination, a cylinder, a reciprocating piston, a distributing valve under constant steam pressure to urge it in one direction, and means controlled by the piston for moving the valve in the opposite direction, such. means being varied in its action on the valve as the piston speed on the instant stroke may vary.

16. In a governor for steam engines, in combination with an engine having a reciprocating piston and a steam supply valve, of valve-shifting mechanism comprising a pair of cooperatin wedge elements, means for moving the we ges, the movement of one of the wedges being timed with the piston movement.

, 17. In a governor for steam engines, in combination with .an engine having a reciprocating piston and a steam valve, of valve-shifting mechanism comprising a pair of cooperating wedges, means for moving the Wedges, and means for varying the relative movement of the wedges in correspondence with variations in the travel speed of the piston.

18. In a governor for steam engines, the

combination with an engine having a reciprocating piston and a steam valve, of valve-shifting mechanism comprising a pair of cooperating wedges, means for reciproeating one of the wedges at constant speed, and means for reciprocating the other wedge at speeds corresponding with the speed of the piston throughout each of its strokes.

19. In a governor. for steam engines, the combination with an engine having a reciprocating piston and a steam valve, of valveshifting mechanism comprising a pair of cooperating wedges, means for reciprocating one of the wedges at constant speed, means for adjusting such speed, and means for re ciprocating the other wedge at speeds corresponding with the speed of the piston throughout each of its strokes.

NATHAN M. LOWER. 

